Get-AllLocalGroupAdmins - Get Active Computers in AD and return the local Administrator group membership. Report as Excel.

Get-AllLocalGroupAdmins.ps1

#requires -version 5.0
<#
.SYNOPSIS
Finds active computers in AD and collects a list of their group memberships

#>

param (
    #Path to output the resulting Excel Report
    [String]$Path = "LocalAdminGroupReport-$(get-date -format yyyyhhmmss).xlsx",
    #Use fancy CIM Method. Only works if winrm remote management is enabled
    [Switch]$CIM,
    #Get all the members of groups and include them in the results rather than the group names
    [Switch]$ExpandGroups
)

#region Prerequisites
$PrerequisiteModules = "poshrsjob","importexcel"
$CurrentUserModulePath = "$home\Documents\WindowsPowerShell\Modules\"
install-module $PrerequisiteModules -scope currentuser -Confirm:$false -ErrorAction stop
$PrerequisiteModules | foreach {
    import-module "$CurrentUserModulePath\$PSItem" -erroraction stop
}
#endregion Prerequisites

#region Includes
Function Get-RemoteGroupMembership
{
    <#
    .SYNOPSIS
       Gather list of all assigned users in all local groups on a computer.  
    .DESCRIPTION
       Gather list of all assigned users in all local groups on a computer.  
    .PARAMETER ComputerName
       Specifies the target computer for data query.
    .PARAMETER IncludeEmptyGroups
       Include local groups without any user membership.
    .PARAMETER ThrottleLimit
       Specifies the maximum number of systems to inventory simultaneously 
    .PARAMETER Timeout
       Specifies the maximum time in second command can run in background before terminating this thread.
    .PARAMETER ShowProgress
       Show progress bar information

    .EXAMPLE
       PS > (Get-RemoteGroupMembership -verbose).GroupMembership

       <output>
       
       Description
       -----------
       List all group membership of the local machine.

    .NOTES
       Author: Zachary Loeber
       Site: http://www.the-little-things.net/
       Requires: Powershell 2.0

       Version History
       1.0.0 - 09/09/2013
        - Initial release
    #>
    [CmdletBinding()]
    param
    (
        [string]
        $ComputerName,
        
        [Parameter(HelpMessage="Include empty groups in results")]
        [switch]
        $IncludeEmptyGroups,

        [Parameter(HelpMessage="Set this if you want the function to prompt for alternate credentials")]
        [switch]
        $PromptForCredential,
        
        [Parameter(HelpMessage="Set this if you want to provide your own alternate credentials")]
        [System.Management.Automation.Credential()]
        $Credential = [System.Management.Automation.PSCredential]::Empty
    )

    PROCESS
    {
        # This is the actual code called for each computer

        Write-Verbose -Message ("Local Group Membership: WMI Query to $computername")
        $WMIHast = @{
            ComputerName = $ComputerName
            ErrorAction = 'Stop'
        }

        # General variables
        $GroupMembership = @()
        $PSDateTime = Get-Date
                
        # Modify this variable to change your default set of display properties
        $defaultProperties    = @('ComputerName','GroupMembership')
        $wmi_groups = Get-WmiObject @WMIHast -Class win32_group -filter "SID = 'S-1-5-32-544'"
        foreach ($group in $wmi_groups)
        {
            $Query = "SELECT * FROM Win32_GroupUser WHERE GroupComponent = `"Win32_Group.Domain='$($group.domain)',Name='$($group.name)'`""
            $wmi_users = Get-WmiObject @WMIHast -query $Query -Verbose
            if (($wmi_users -eq $null) -and ($IncludeEmptyGroups))
            {
                [PSCustomObject][Ordered]@{
                    'Computername' = $ComputerName
                    'Group' = $group.Name
                    'GroupMember' = ''
                    'MemberType' = ''
                }
                
            }
            else
            {
                foreach ($user in $wmi_users.partcomponent)
                {
                    if ($user -match 'Win32_UserAccount')
                    {
                        $Type = 'User'
                    }
                    elseif ($user -match 'Win32_Group')
                    {
                        $Type = 'Group'
                    }
                    elseif ($user -match 'Win32_SystemAccount')
                    {
                        $Type = 'SystemAccount'
                    }
                    else
                    {
                        $Type = 'Other'
                    }

                    #Output the result
                    [pscustomobject][ordered]@{
                        'ComputerName' = $ComputerName
                        'Group' = $group.Name
                        'GroupMember' = (($user.replace("Domain="," , ").replace(",Name=","\").replace("\\",",").replace('"','').split(","))[2]).trim()
                        'Type' = $Type
                    }
                    
                }
            }
        }
}
}

#endregion Includes

#region Main
$activeServerList = get-adcomputer -Properties lastlogondate -filter {operatingsystem -like "*Server*" -and enabled -eq $true} | 
    where lastlogondate -gt (get-date).adddays(-30) | 
    sort lastlogondate -Descending |
    select -expandproperty dnshostname
$batchID = "GetRemoteGroups-" + $(new-guid).guid

$localGroupMemberships = $activeServerList | start-rsjob -FunctionsToLoad "Get-RemoteGroupMembership" -batch $batchID {
    $ComputerName = $PSItem
    write-verbose "Getting Administrator Group Members of $ComputerName"
    if ($USING:CIM) {
        try {
            get-ciminstance -computername $ComputerName -classname win32_group -filter "Name = 'administrators'" -ErrorAction Stop | 
            get-cimassociatedinstance -association win32_groupuser -ErrorAction Stop

        } catch {
            $PSItem
            #write-warning "$ComputerName`: Failed to collect local admin information. Error: $PSItem"
        }
    } else {
        Get-RemoteGroupMembership -ComputerName $ComputerName | where 
    } #else
} | 
    wait-rsjob -ShowProgress | 
    receive-rsjob

$localGroupMemberships | export-excel -path $Path -WorkSheetname "Local Admins" -TableName "LocalAdmins"

remove-rsjob -batch $batchID -force

#Get the SID of the group using .NET function
$localGroupMemberships | where type -match "Group" | select -ExpandProperty GroupMember -unique | foreach {
    $groupDomain = ($PSItem -split '\\')[0]
    $groupName = ($PSItem -split '\\')[1]
    $groupSID = (new-object System.Security.Principal.NTAccount($groupDomain, $groupName)).translate([System.Security.Principal.SecurityIdentifier]).value
    
    #Generate the group membership entries
    (get-adgroupmember $groupSID -recursive -ErrorAction stop) | foreach {
        [PSCustomObject]@{
            Domain = $groupDomain
            Name = $groupName
            SID = $groupSID
            Member = $PSItem.samaccountname
            MemberDisplayName = $PSItem.name
        }
    }
} | export-excel -path $Path -WorkSheetname "AD Groups" -TableName "ADGroups"

#endregion Main